This subproject is one of many research subprojects utilizing the resources provided by a Center grant funded by NIH/NCRR. Primary support for the subproject and the subproject's principal investigator may have been provided by other sources, including other NIH sources. The Total Cost listed for the subproject likely represents the estimated amount of Center infrastructure utilized by the subproject, not direct funding provided by the NCRR grant to the subproject or subproject staff. Recent work has demonstrated that expression of SIV antigens from a RhCMV vector stimulates protective immune responses following multiple low-dose rectal challenge with SIVmac239. Translation of these findings to human clinical trials will depend, in large part, on demonstration that the RhCMV vector is sufficiently attenuated to prevent vector-associated pathological outcomes. Primarily, this means demonstration that the RhCMV vector cannot cross the placenta and congenitally infect the fetus. This has not been possible to date because there have not been any breeding age macaques that are uninfected with RhCMV. The Specific Pathogen Free (SPF) cohort now provides the opportunity to advance the translation of the findings about RhCMV as a vaccine vector by evaluating the safety of the vector in the nonhuman primate model. As such, this meets the intent and spirit of the parent grant by augmenting the utility of the SPF animals for AIDS-related research.